Making graphite for crucibles?

Maybe you know the YouTube channel "Primitive Technology". He shows, among other things, how to build a shelter out of nothing in nature, how to make clay pottery and even how to extract iron. However, so far he has only managed to melt cast iron with a high carbon content.

I now plan to develop these ideas further and to do so I need to melt iron in order to continue reducing the carbon.

For this I plan to build a melting crucible because a simple clay crucible has too low a melting point for it and according to my research a graphite crucible with 1700 ° would be sufficient, I have to build one (only with natural means).

So my question is, how can I get graphite for such a crucible?

I've read several times now that coal is nothing other than graphite. Can I use coal for this or would the crucible melt?

Thank you in advance and sorry that I didn't ask the question precisely enough the first time